From a52e5cdbe8016d4e3e6322fd93d71afddb9a5af9 Mon Sep 17 00:00:00 2001
From: Sven Schnelle <svens@linux.ibm.com>
Date: Tue, 7 Mar 2023 14:35:23 +0100
Subject: [PATCH] s390/ipl: add missing intersection check to ipl_report
handling
The code which handles the ipl report is searching for a free location
in memory where it could copy the component and certificate entries to.
It checks for intersection between the sections required for the kernel
and the component/certificate data area, but fails to check whether
the data structures linking these data areas together intersect.
This might cause the iplreport copy code to overwrite the iplreport
itself. Fix this by adding two addtional intersection checks.
Cc: <stable@vger.kernel.org>
Fixes: 9641b8cc733f ("s390/ipl: read IPL report at early boot")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
---
arch/s390/boot/ipl_report.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/s390/boot/ipl_report.c b/arch/s390/boot/ipl_report.c
index 9b14045065b6e..74b5cd2648622 100644
--- a/arch/s390/boot/ipl_report.c
+++ b/arch/s390/boot/ipl_report.c
@@ -57,11 +57,19 @@ repeat:
if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_data.start && initrd_data.size &&
intersects(initrd_data.start, initrd_data.size, safe_addr, size))
safe_addr = initrd_data.start + initrd_data.size;
+ if (intersects(safe_addr, size, (unsigned long)comps, comps->len)) {
+ safe_addr = (unsigned long)comps + comps->len;
+ goto repeat;
+ }
for_each_rb_entry(comp, comps)
if (intersects(safe_addr, size, comp->addr, comp->len)) {
safe_addr = comp->addr + comp->len;
goto repeat;
}
+ if (intersects(safe_addr, size, (unsigned long)certs, certs->len)) {
+ safe_addr = (unsigned long)certs + certs->len;
+ goto repeat;
+ }
for_each_rb_entry(cert, certs)
if (intersects(safe_addr, size, cert->addr, cert->len)) {
safe_addr = cert->addr + cert->len;
--
2.30.2